In a gymnasium, stadium or the like, since various sports are played, lines are installed according to the sporting event. In the related art, lime or paint is used, or cloths, strings and the like are used for the installation of lines. When different sports are played, the lines are erased or removed and lines are reinstalled anew. However, there is a problem that such erasure or removal of the lines and reinstallation of lines take time and effort. Moreover, in some cases, lines for plural sporting events are installed in advance in a coexisting manner in a gymnasium or stadium but athletes become confused.
Patent Document 1 discloses a system for assisting the work of installing different field lines for each sport in a multipurpose stadium, utilizing a wireless IC tag buried in advance in the stadium and a portable computer capable of reading the wireless IC tag.